The Ulfberht swords are about 170 medieval swords found in Europe, dated to the 9th to 11th centuries, with blades inlaid with the inscription VLFBERH T or VLFBERHT . These swords used a harder and more flexible steel than other swords of the same period due to its higher percentage of carbon in the steel. The word "Ulfberht" is a Frankish personal name that became the basis of a trademark of sorts, used by multiple bladesmiths for several centuries.
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